1. Field of the Invention
The present invention relates to the field of electrosurgery, and more particularly to systems and methods for ablating, cauterizing and/or coagulating body tissue using radio frequency energy. More in particular, the systems utilize voltage threshold means for controlling the voltage applied to tissue in a cycle-to-cycle manner.
Radio frequency ablation is a method by which body tissue is destroyed by passing radio frequency current into the tissue. Some RF ablation procedures rely on application of high currents and low voltages to the body tissue, resulting in resistive heating of the tissue which ultimately destroys the tissue. These techniques suffer from the drawback that the heat generated at the tissue can penetrate deeply, making the depth of ablation difficult to predict and control. This procedure is thus disadvantageous in applications in which only a fine layer of tissue is to be ablated, or in areas of the body such as the heart or near the spinal cord where resistive heating can result in undesirable collateral damage to critical tissues and/or organs.
It is thus desirable to ablate such sensitive areas using high voltages and low currents, thus minimizing the amount of current applied to body tissue.